Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful behavioral context beyond annotations: it is a live source, can return HTTP 503 when upstream data is unavailable for more than 50% of fields, is not charged on failure, and costs $0.02 USDC per call.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is dense but efficient, front-loading the core purpose before adding source, failure behavior, and pricing. Every sentence adds useful information, and there is no filler or repetition of schema details.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a tool with a single optional parameter and no output schema, the description explains the benchmark contents, sources, failure mode, and pricing. It does not describe the output structure or the exact behavior of the 'all' asset option, which are minor gaps given the simplicity of the tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has one optional enum parameter, asset, with 0% description coverage. The description lists USDC/USDT/DAI, which maps to the enum values, but it does not explain the behavior of the 'all' value, the default when omitted, or how the mentioned TVL filter relates to the parameter. It partially compensates but leaves gaps.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific verb and resource: retrieving stablecoin lending yield benchmarks. It clearly enumerates assets (USDC/USDT/DAI), protocols, chains, and metrics, which distinguishes it from the broad sibling tools like get_defi_yield_benchmark.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context for when this tool is relevant: whenever an agent needs stablecoin lending APY benchmarks across major protocols and chains. It does not explicitly name alternatives or exclusion conditions, but the scope is specific enough to route correctly.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.